Connectors in which the plug element is fastened by a bayonet-like connection to the socket element, are known, for example, from EP 1 024 559 A2.
To connect the plug element to the socket element, the plug element is positioned on the socket element, wherein the plug housing is inserted into the socket element. The socket housing has a plurality of spiral-shaped guide grooves which are distributed over the outer circumference and into which a corresponding number of guide lugs engage when the plug element is inserted, said guide lugs being disposed over the inner circumference of a coupling ring. The guide grooves and the guide lugs form the bayonet-like connection. Rotating the coupling ring around the longitudinal axis of the plug element causes the guide lugs to slide along the oblique guide grooves and the plug element to be pulled against the socket element. To prevent the plug element from becoming unintentionally detached from the socket element, end positions are disposed at the end of the guide grooves in, for example, the form of a recess oriented in the opposite direction to that in which the plug element is inserted in the socket element and into which the guide lugs engage at the end position, i.e., at the end of the rotational movement of the coupling ring. Between the plug element and the socket element, elastic structure which are compressed by the rotary movement of the coupling ring come into effect. The elastic structure comprise, for example, a spring—in particular, a cup spring or a spring washer—or a seal or a sealing ring made of an elastic material, e.g., rubber or plastic. When the end position is reached, the spring forces of the elastic structure press the guide lugs into the end positions and hold them there. In this way, an unintentional unscrewing of the bayonet-like connection between the plug element and the socket element is to be prevented. The reliability and durability of the bayonet-like connection system is essentially determined by the mechanical stability of the connector, on the one hand, and the elasticity of the elastic structure, on the other.
These known connectors with the bayonet-like connecting system between the plug element and the socket element represent, in fact, an improvement over the plug connectors with a simple thread between the plug element and the socket element, but are not able under extreme mechanical loads (for example, vibrations, jolts, and so on) to ensure a stable, long-term connection between the plug element and the socket element, since the elastic structure lose their elastic properties over time.